Net install problems

I'm having problems with the net install of 5.5 with only Xfce for a friend.

Firstly, it requires ethernet and doesn't work with wireless so I had to take the computer to my place as I have ethernet.

I installed Trisquel console version (had to use space key to select it which isn't mentioned in the net install) and encrypted hard disks (without encryption grub did not show up at all - selecting which partitions to encrypt after creating them also requires pressing space key).

Encrypted devices require adding a mount point again - the installer doesn't remember the mount point provided for the partition when creating the partition.

Also, even if I encrypt /home partition later on the installer suggests encrypting it again when mounting after entering password. I just used this encryption method, but the partition apparently mounts fine without password from live CD. I'm guessing the contents are protected then? The third (non-home) encrypted partition asks for password when using live CD.

Grub shows up every two boots I have no idea why. ctrl+alt+delete usually reboots.

I needed to add "nomodeset" to get grub to show text. Text appeared but didn't reach a terminal unless I used alt+ctrl+f1.

Then I installed xfce and gdm and network-manager. It works on my Samsung 1080P monitor but boot sometimes takes more than a minute (it is waiting for network manager), but a friend has a higher resolution 2560x1440 Dell monitor and it simply shut down after entering password in gdm.

Chrooting and replacing gdm by lightdm didn't help. I'm guessing it's a xorg.conf problem then? Live CD works fine and shows correct resolution. The computer has integrated intel graphics (core i7).

What can I do to fix the issue? Should I use the xorg.conf file from live CD? How to boot without nomodeset?

Thanks for your help